title: Selective laser trabeculoplasty: Does energy dosage predict response?
abstract: BACKGROUND
  Selective laser trabeculoplasty (SLT) is a widely used treatment for open angle glaucoma, producing sustained reductions of intraocular pressure (IOP). The aim of this study was to evaluate the long-term relationship between SLT energy dosage and IOP reduction.
  
  
  METHODS
  A retrospective review was performed for patients receiving primary SLT therapy, with inclusion of subjects treated with 360° of SLT. Energy settings were collected upon treatment and IOP was collected at baseline up to 36 months. Pearson's correlation coefficient was used to determine whether there was a significant correlation between SLT energy and IOP reduction at all time points. Kaplan-Meier analysis with log-rank test was performed to determine the differences in IOP reduction ≥20% from baseline among those treated with low (<85 mJ), medium (85-105 mJ), and high (>105 mJ) energy SLT.
  
  
  RESULTS
  A total of 104 eyes (75 patients) were included. The mean total SLT energy was 93.73 mJ (standard deviation (SD) = 21.83 mJ, range: 34.4-122 mJ). A significant positive correlation (P ≤ 0.05) between the amount of energy delivered and IOP reduction was found at all time points. Log-rank test showed a significant difference in IOP reduction ≥20% from baseline between the three energy groups, with low energy patients experiencing failure at an earlier time (P = 0.05).
  
  
  CONCLUSIONS
  Within the range of total energy examined, there is a positive correlation between total energy used and amount of pressure reduction achieved at up to 3 years of follow-up. This may be useful in determining the optimal energy dosage for maximum effect for patients receiving SLT.
authors.affiliation: Institute of Ophthalmology and Visual Science, Rutgers New Jersey Medical School, Newark, NJ USA.
authors.forename: Larissa
authors.initials: L
authors.lastname: Habib
authors.forename: James
authors.initials: J
authors.lastname: Lin
authors.forename: Tamara
authors.initials: T
authors.lastname: Berezina
authors.forename: Bart
authors.initials: B
authors.lastname: Holland
authors.forename: Robert D
authors.initials: RD
authors.lastname: Fechtner
authors.forename: Albert S
authors.initials: AS
authors.lastname: Khouri
keywords: Glaucoma; laser therapy; selective laser trabeculoplasty